558 



INDEX 



vaccination, 139; 537. 



vacuole, 147. 



variation, 328. 



vascular bundles, 80. 



veins, 399, 400. 



ventilation, 389, 429, 430. 



ventricle, 397. 



vertebrates, 158; development of, 



235; classes and characteristics, 



236. 

 Von Behring, a German bacteriologist, 



142; helped develop anti-toxin for 



diphtheria, 539. 

 Von Bunge, Dr., quoted on alcohol 



515, 518. 

 villi, 373. 

 vitamines, 356. 



W 



Wallace, Alfred Russell, English 



scientist, 328, 541. 

 water, 19, 23; necessity of, for plants, 



58; vapor, 91; supervision of 



supply, 441. 

 wax, 215. 



wheat, 448, 449; improved, 489. 

 White, Dr. Andrew D., quoted, 510. 

 whooping cough, 137. 

 Wiley, Dr. Harvey, 521. 

 Williams, Dr. H. W., quoted, on 



death rate in World War, 441. 

 wind, agent in pollenation, 111, 113. 

 wood (root), 51, 56; stern, 76; fiber, 



78; hard and soft, 505. 

 Woodhead, Dr., quoted on alcohol, 



517. 



workers (honey bees), 213, 215. 

 World War, low loss from infectious 



diseases, 441. 

 worms, parasitic: tape, hook, trichina, 



164-169, 234, 470; see earthworm. 



yellow fever, 151; conquest of by 

 Drs. Reed, Carrol, Lazear and 

 Agramonte, 229; see protozoa, 469. 



yeast plants (fungi), 130. 



zoology, 2. 



